- vcf-midatlantic - lists.vcfed.org

ADM-3A display problem
by Herb Johnson 25 May '17

25 May '17

I own and have repaired some ADM-3A terminals, and I have electronics experience from the era. I did not see the posted image, from the VCF Web archive of messages. I just walked through the ADM-3A Maintenance Manual, which is on Web online archives. I did not see any "invert video" DIP switch setting. I did not see any description about how to invert video. And - at a glance - I did not see anything on the schematic on the logic board, which suggested a simple means to invert video. Of course I may have missed something; or my manual may not match the actual terminal. But I'm confirming the owner's impression that there's not likely a "toggle switch" in play. I'm afraid, the apparent inverted video, may be a real issue and not just some inadvertent setting. So: it's either a deliberate "mod" for purpose, or some logic failure. I doubt it's a monitor failure - that can be diagnosed, by using an oscilloscope to look at the incoming CRT monitor signal, to see if it is standard NTSC type video. This calls for technical experience and use of an oscilloscope. An oscilloscope will show actual signals. If there is a mod, jumper or failure, "walking through" with schematic and oscilloscope will find it. The logic board should be inspected for any wiring modifications. The board can be removed and decabled for such inspections. Be VERY CAREFUL because 1) various pieces of insulating "cardboard" are EXTREMELY fragile, 2) there's risk of shock from the 15,000 volts on the CRT - a charge that the "tube" retains after power-off, and 3) of course any physical issues from handing old electronics, boards, cabinets. Standard disclaimer: I'm not responsible for loss, injury or damage. Use any information I provide at your own risk. I may be wrong, confirm anything I've suggested. Herb Johnson -- Herbert R. Johnson, New Jersey in the USA http://www.retrotechnology.com OR .net preserve, recover, restore 1970's computing email: hjohnson AT retrotechnology DOT com or try later herbjohnson AT retrotechnology DOT info

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Computing time in BASIC
by Evan Koblentz 25 May '17

25 May '17

Suppose I want an Applesoft (Microsoft) BASIC program to do something for a certain amount of time as measured in seconds or minutes. FOR-NEXT loops don't align to any real increment -- they just count based on how fast the processor can go, right? If so, then how do you make something happen for a time amount? ------------------------- Evan Koblentz, director Vintage Computer Federation A 501(c)3 educational non-profit Evan(a)vcfed.org (646) 546-9999 www.vcfed.org facebook.com/vcfederation twitter.com/vcfederation

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Film thing is resolved
by Evan Koblentz 25 May '17

25 May '17

Everyone, There was extensive discussion about the film issue on the private chapter admin list (me, Jeff B., Corey, Dean). We four jointly drafted a letter to IA management. Corey and I signed it. I met with IA management today and the matter is resolved. VCF is satisfied with the outcome. Please understand that I can't go into details, and that it would NOT help if any of our members post any further Facebook comments about it. ________________________________ Evan Koblentz, director Vintage Computer Federation a 501(c)(3) educational non-profit evan(a)vcfed.org (646) 546-9999 www.vcfed.org facebook.com/vcfederation twitter.com/vcfederation instagram.com/vcfederation

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Re: [vcf-midatlantic] Commodore 64 curb find, need power supply
by Alexander 25 May '17

25 May '17

Nice score! I believe I have a spare C64 PSU from a bricked machine that won't be needing it. You are welcomed to it. You're over in Springfield, right? I'm not far away, if you want to stop by the Merrifield area, it's yours at your convenience. -Alexander 'Z' Pierson Sent from my pocket telephone. Jason Perkins via vcf-midatlantic <vcf-midatlantic(a)lists.vintagecomputerfederation.org> wrote: >Last week I was driving through my neighborhood and spied an electric lawn >mower by the curb. When I walked back to nab it, by eye caught a Commodore >logo on a box. I thought to myself "Surely there's not commodore equipment >inside." Turns out it was a never opened MPS-801 dot matrix printer! >Everything, even the original ribbon, was in its packing. > >Well, this warranted a closer look at the other curb items. Nearby was a >long box lid, with 2 items in plastic bags. One bag contained 1541 drive, >and the other an original style C64. Both with plastics in perfect >condition! The C64 has an "A" revision motherboard. > >I've never had a C64, so I figure this is worth a play :) It didn't come >with a power supply though. Does anyone have an extra they want to sell? >I'm just outside DC if that makes a difference. > >Thanks! > >-- >Jason Perkins >313 355 0085

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Commodore 64 curb find, need power supply
by Jason Perkins 24 May '17

24 May '17

Last week I was driving through my neighborhood and spied an electric lawn mower by the curb. When I walked back to nab it, by eye caught a Commodore logo on a box. I thought to myself "Surely there's not commodore equipment inside." Turns out it was a never opened MPS-801 dot matrix printer! Everything, even the original ribbon, was in its packing. Well, this warranted a closer look at the other curb items. Nearby was a long box lid, with 2 items in plastic bags. One bag contained 1541 drive, and the other an original style C64. Both with plastics in perfect condition! The C64 has an "A" revision motherboard. I've never had a C64, so I figure this is worth a play :) It didn't come with a power supply though. Does anyone have an extra they want to sell? I'm just outside DC if that makes a difference. Thanks! -- Jason Perkins 313 355 0085

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OT - electronics question
by william degnan 24 May '17

24 May '17

There is a "thing" that one can use to regulate LED voltages in a string, with a pretty large voltage/resistance variation. It's better than having a resistor at each light. What is this thing called?

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Re: [vcf-midatlantic] COBOL
by Kenneth Seefried 24 May '17

24 May '17

Something I've noticed being overlooked whenever this topic comes up (what, several times a year): the industry *has* been trying to migrate off COBOL for as long as I've been in the game (30+ years). At one point, the "4GL" suites were going to let you capture all that business logic in a 'better' language. Most are all long forgotten and barely lamented. PowerBuilder, anyone? Then IBM decided the answer to COBOLness was, of all things, Smalltalk. They dumped all kinds of resources into retreading COBOL programmers into object-oriented quiche-eaters. A glorious experiment; I think pretty much the only legacy is Object COBOL and a lot of programmers that really, really hate the whole OO paradigm. Then about a decade ago I guess, Java was going to put the final stake in COBOLs heart. Jury still out there, I suppose. I do see a *lot* of business apps for conservative, disciplined, COBOL-esque IT shops being done in Java. Not sure they're replacements, tho. I've even heard of real projects to migrate COBOL to Ada (reasonable), Visual BASIC (icky) and C (kill it with fire). I'm sure over time all these 'alternatives' eroded away the *number* of COBOL apps in production; after all, if you've got some smallish, auxiliary app why not make it easier for more people to be competent to maintain. And there's an entire ecosystem of products that let you put a nice UI in front of what is on the back-end a block-oriented, 3270 terminal abstraction. All programmable in VB, Javascript, etc. What seems clear, however, is that little migration of business critical, high volume, high reliability transaction processing applications that are COBOL/Mainframe core competencies is being seriously undertaken. P.S. - If you're really interested in learning COBOL academically, take a peek at Columbus State University TSYS School of CS (https://goo.gl/0cx6qH) You can get a COBOL/Mainframe oriented certificate or BS degree. It's a joint venture of sorts between the University System of Georgia, IBM and TSYS, who is one of the largest credit card processors in the world. This is a tangible answer to "not enough new COBOL programmers". P.P.S. - I'm currently an IT executive at the 5th largest bank in the US. Yes we use COBOL. No, it's not going away any time soon. They're hiring, last I checked. KJ

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Re: [vcf-midatlantic] Computing time in BASIC
by william degnan 24 May '17

24 May '17

There was a whole industry in 8bit times selling clock cards with batteries. I have also seen replacement chips with clock/batteries on them. Not sure what specifically was used for your machine to accomplish this but that's one thing you can do, IF the clock writes to a memory location that BASIC can then access. Poor man's alternative, use a stopwatch and run the program. Have an on-screen counter running that shoes your program loop counter maybe a space bar to force a stop. Eventually you'll find the best method to accomplish. Help? Bill Degnan twitter: billdeg vintagecomputer.net On May 24, 2017 1:03 AM, "Evan Koblentz via vcf-midatlantic" < vcf-midatlantic(a)lists.vintagecomputerfederation.org> wrote: Suppose I want an Applesoft (Microsoft) BASIC program to do something for a certain amount of time as measured in seconds or minutes. FOR-NEXT loops don't align to any real increment -- they just count based on how fast the processor can go, right? If so, then how do you make something happen for a time amount? ------------------------- Evan Koblentz, director Vintage Computer Federation A 501(c)3 educational non-profit Evan(a)vcfed.org (646) 546-9999 www.vcfed.org facebook.com/vcfederation twitter.com/vcfederation

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OT: What would you do with a 1Gbps connection to the internet?
by Joseph Oprysko 24 May '17

24 May '17

Just an interesting topic of conversation, since Verizon has the 960/880 connection, and Comcast is rolling out the 960/35 connections in the area. -- Normal Person: Hey, it seems that you know a lot. Geek: To be honest, it's due to all the surfing I do. Normal Person: So you go surfing? Normal Person: But I don't think that has anything to do with knowing a lot... Geek: I think that's wrong on a fundamental level. Normal Person: Huh? Huh? What?

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Exciting UNIVAC artifacts
by Evan Koblentz 23 May '17

23 May '17

Some of you may have heard that the Unisys Blue Bell (Penn.) Retirees Group recently closed due to lack of mission/membership. They donated all of their artifacts to VCF. The shipment will arrive soon. They said its contents include: - Digital and printed copies of their "Newsbits" newsletter from the mid-1980s to present, most issues are there - UNIVAC I programming guide (will pair nicely with the UNIVAC 1 technical guide they already donated a few years ago) - 50TH anniversary celebration book - CDs with interviews of Univac 1 workers - Ridge Ave. (their old factory) dedication book - Documents/photos "of the early days of Eckert-Mauchly Corp." ________________________________ Evan Koblentz, director Vintage Computer Federation a 501(c)(3) educational non-profit evan(a)vcfed.org (646) 546-9999 www.vcfed.org facebook.com/vcfederation twitter.com/vcfederation instagram.com/vcfederation

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